Fan assembly

ABSTRACT

A fan assembly includes a nozzle having a first casing section, a second casing section, an air inlet, an air outlet, and an interior passage for conveying air from the air inlet to the air outlet. The nozzle defines a bore through which air from outside the fan assembly is drawn by air emitted from the nozzle. The nozzle is detachably mounted on a body including a motor and impeller unit for generating an air flow through the interior passage, and a humidifier for humidifying the air flow before it enters the interior passage. The first casing section defines, at least in part, the interior passage, and is detachable from the second casing section to allow the interior passage to be accessed by a user for cleaning.

REFERENCE TO RELATED APPLICATIONS

This application claims the priority of United Kingdom Applications Nos.1301574.8 and 1301575.5, both filed Jan. 29, 2013, the entire contentsof which are incorporated herein by reference.

FIELD OF THE INVENTION

The present invention relates to a fan assembly. In a preferredembodiment, the present invention provides a humidifying apparatus forgenerating a flow of moist air and a flow of air for dispersing themoist air within a domestic environment, such as a room, office or thelike.

BACKGROUND OF THE INVENTION

Domestic humidifying apparatus is generally in the form of a portableappliance having a casing comprising a water tank for storing a volumeof water, and a fan for creating a flow of air through an air duct ofthe casing. The stored water is conveyed, usually under gravity, to anatomizing device for producing water droplets from the received water.This device may be in the form of a heater or a high frequency vibratingdevice, such as a transducer. The water droplets enter the flow of airpassing through the air duct, resulting in the emission of a mist intothe environment. The appliance may include a sensor for detecting therelative humidity of the air in the environment. The sensor outputs asignal indicative of the detected relative humidity to a drive circuit,which controls the transducer to maintain the relative humidity of theair in the environment around a desired level. Typically, the actuationof the transducer is stopped when the detected relative humidity isaround 5% higher than the desired level, and is restarted when thedetected relative humidity is around 5% lower than the desired level.

The flow rate of the air emitted from such a humidifier tends to berelatively low, for example in the range from 1 to 2 litres per second,and so the rate at which the humid air is dispersed into a room can bevery low. Furthermore, as the relative humidity of the air in the localenvironment of the humidifier will rise relatively rapidly in comparisonto that of the air in the local environment of the user, the relativehumidity detected by the sensor will not, at least initially, beindicative of the relative humidity of the air local to the user. As aresult, the actuation of the transducer may be stopped when the relativehumidity of the air in the local environment of the user issignificantly below the desired level. Due to the relatively low rate atwhich the humid air is dispersed into the room, it can then take sometime for the detected relative humidity to fall to a level at which theactuation of the transducer is restarted. Consequently, it may take along period of time for the relative humidity of the air in the localenvironment of the user to reach the desired level.

WO 2010/100462 describes humidifying apparatus which comprises ahumidifier for emitting moist air into the atmosphere, and, positionedin front of the humidifier, a fan assembly which comprises a bodyhousing a motor-driven impeller for creating an air flow, and an annularnozzle mounted on the body which comprises an interior passage receivingthe air flow and an air outlet for emitting the air flow. The nozzledefines a bore through which both air from outside the nozzle and themoist air emitted from the humidifier are drawn by the air flow emittedfrom the mouth. The outlet of the humidifier is located at the samelevel as the lowermost portion of the bore of the nozzle. Through theentrainment of the moist air emitted from the humidifier within an aircurrent generated by the fan assembly, the moist air can be rapidlyconveyed away from the humidifier to a distance of up to several metres.This can enable a user located at this distance from the humidifier toexperience a rapid rise in the relative humidity of the air in the localenvironment.

SUMMARY OF THE INVENTION

In a first aspect, the present invention provides a fan assemblycomprising:

-   -   a nozzle having a first section having at least one first air        inlet, at least one first air outlet, and a first interior        passage for conveying air from said at least one first air inlet        to said at least one first air outlet; and a second section        having at least one second air inlet, at least one second air        outlet, and a second interior passage for conveying air from        said at least one second air inlet to said at least one second        air outlet, at least one of the first and second sections of the        nozzle defining a bore through which air from outside the fan        assembly is drawn by air emitted from the nozzle; and    -   a body on which the nozzle is mounted, the body comprising flow        generating means for generating a first air flow through the        first interior passage and a second air flow through the second        interior passage, and means for changing one of the humidity and        composition of the second air flow before it enters the second        interior passage;    -   wherein the second section of the nozzle comprises a detachable        casing section defining, at least in part, the second interior        passage.

In an illustrated embodiment, the fan assembly includes a humidifier forhumidifying the second air flow, but the fan assembly may alternativelycomprise one of a heater, a chiller, an air purifier and an ionizer forchanging another parameter of the second air flow.

A difference between the fan assembly of the present invention, whenused to emit a humidified air current, and the humidifying apparatusdescribed in WO 2010/100462 is that in the present invention, the nozzleof the fan assembly is arranged to emit both the moistened second airflow and the first air flow which carries the moistened air flow intothe environment. In contrast, in WO 2010/100462 the moistened air flowis emitted from an outlet of the humidifying apparatus located behindthe fan assembly, and entrained within a lower part of the air flowgenerated by the fan assembly. The present invention can thus allow themoistened air flow to be emitted from one or more different air outletsof the nozzle. These air outlets may be positioned, for example, aboutthe bore of the nozzle to allow the moistened air flow to be dispersedrelatively evenly within the first air flow. By locating the componentsthat change the humidity of the second air flow within the body, thesecond section of the nozzle can have a relatively small size incomparison to the first section of the nozzle. The present invention canthus allow the humidifying apparatus to have a compact appearance, areduced number of components and therefore reduced manufacturing costs.

The second section of the nozzle comprises a detachable casing sectiondefining, at least in part, the second interior passage. Throughdetachment of this detachable casing section from the remainder of thenozzle, the second interior passage of the nozzle may be periodicallyaccessed for cleaning by the user to remove any moisture or other matterwhich may remain in the second interior passage when the fan assembly isswitched off.

The detachable casing section is preferably arranged to define, at leastin part, the second air outlet(s). Removal of the detachable casingsection can thus enable the second air outlet(s) to be easily cleaned bythe user. The detachable casing section preferably comprises the secondair inlet(s).

The bore is preferably defined by both of the first and second sectionsof the nozzle. The detachable casing section is preferably annular inshape. The detachable casing section may comprise a plurality ofcomponents, but in a preferred embodiment the detachable casing sectioncomprises a single annular component. The second section of the nozzleis preferably a front section of the nozzle, and the first section ofthe nozzle is preferably a rear section of the nozzle.

In a preferred embodiment, the detachable casing section is a frontcasing section of the nozzle, which defines an annular front end of thenozzle. Each of the first air outlet(s) and the second air outlet(s) isarranged to emit air over at least part of the detachable casing sectionto maximise the volume of air which is drawn through the bore by the airemitted from the nozzle. The detachable casing section preferablycomprises a diffuser surface over which each of the first air outlet(s)and the second air outlet(s) is arranged to emit air.

The nozzle preferably comprises a second casing section which defineswith the detachable casing section the second interior passage, and towhich the detachably casing section is detachably attached. Thedetachable casing section may thus be referred to as a first casingsection of the nozzle. The detachable casing section may be attacheddirectly to the second casing section. Alternatively, the detachablecasing section may be attached directly to a third casing section orother part of the nozzle to which the second casing section isconnected.

The detachment of the detachable casing section from the second casingsection, and its subsequent reattachment to the second casing section,are preferably performable manually so that the user does not require atools or other implement to detach and re-attach the detachable casingsection. In a preferred embodiment the detachable casing section isdetachably attached to the second casing section by a snap-fitconnection, but other means for detachably attaching the detachablecasing section to the second casing section may be used. For example,one or magnets, clips or other manually operable fasteners may beprovided for detachably attaching the detachable casing section to thesecond casing section.

To detach the detachable casing section from the second casing section,the user may pull the detachable casing section from the second casingsection. Where the attachment is effected by a snap-fit connection, thecasing sections preferably comprises a first set of interconnectingmembers located on the detachable casing section, and a second set ofinterconnecting members located on the second casing section. One set ofinterconnecting members may comprise a plurality of protrusions, and theother set of interconnecting members may comprise a plurality ofrecesses each for receiving a respective protrusion to connect thecasing sections. The first set of interconnecting members are preferablylocated on a resilient wall of the detachable casing section to allowthe protrusions to move out of the recesses when the user pulls thedetachable casing section to separate the casing sections.

The second section may comprise a single continuous air outlet, whichmay extend about the front end of the nozzle. Alternatively, the secondsection may comprise a plurality of air outlets, which may be arrangedabout the bore. For example, the second air outlets may be located onopposite sides of the front end of the nozzle. Each of the second airoutlets may comprise one or more apertures, for example, a slot, aplurality of linearly aligned slots, or a plurality of apertures.

The second casing section preferably defines with the detachable casingsection the second air outlet(s). The second air outlet(s) arepreferably defined by an external surface of the detachable casingsection and an internal surface of the second casing section. One ofthese surfaces may comprise a plurality of spacers spaced along thatsurface for engaging the other surface to maintain a relatively constantoutlet size along the length of the second air outlet(s).

The second casing section is preferably annular in shape. The secondcasing section preferably defines part of the bore of the nozzle. Thesecond casing section may define, at least in part, the first interiorpassage. The first interior passage is preferably isolated from thesecond interior passage by a wall of the second casing section, but arelatively small amount of air may be bled from the first interiorpassage to the second interior passage to urge the second air flowthrough the second air outlet(s).

The second casing section preferably defines, at least in part, thefirst air outlet(s). The first section of the nozzle may comprise asingle air outlet, which preferably extends about the bore of thenozzle, and is preferably centred on the axis of the bore.

Alternatively, the first section of the nozzle may comprise a pluralityof air outlets which are arranged about the bore of the nozzle. Forexample, the first air outlets may be located on opposite sides of thebore. The first air outlet(s) are preferably arranged to emit airthrough at least a front part of the bore. The nozzle preferablycomprises a diffuser located downstream from the first air outlet(s).The second casing section may comprise a first portion of the diffuserand the detachable casing section may comprise a second portion of thediffuser located downstream from the first portion. These two portionsof the diffuser may be separated by the second air outlet(s).

The nozzle is preferably detachable from the body. The detachable casingsection is preferably detachable from the second casing section onlywhen the nozzle is detached from the body. This can prevent anyaccidental detachment of the detachable casing section during use of thefan assembly. The detachable casing section preferably comprises a basefor receiving the second air flow, and this base may be graspable by auser to detach the detachable casing section from the second casingsection. The base of the detachable casing section is preferably locatedsubstantially fully within the body when the nozzle is mounted on thebody.

The fan assembly preferably comprises nozzle retention means forattaching the nozzle to the body. The nozzle retention means ispreferably moveable relative to both the nozzle and the body to allowthe nozzle to be removed from the body. The body preferably comprises ahousing or cavity in which the nozzle retention means is located so asto be moveable relative to the body and the housing. The body preferablycomprises a user-operable member for moving the nozzle retention means.In a preferred embodiment, the body comprises a user-operable buttonwhich is preferably depressible by the user to move the nozzle retentionmeans from a retaining position for attaching the nozzle to the body toa release position for releasing the nozzle for removal from the body.The nozzle retention means is preferably biased towards the retainingposition, for example by one or more springs located between the bodyand the nozzle retention means.

The nozzle retention means is preferably arranged to engage a base ofthe second section of the nozzle to retain the nozzle on the body. Thenozzle retention means may comprise a plurality of moveable detents, andthe nozzle comprises means for receiving the detents. The detents may beconnected to a carrier member, which is preferably in the form of a hoopor ring which extends about the base of the nozzle when the nozzle isattached to the body. The body preferably comprises a plurality ofapertures through which the detents protrude to engage said means forreceiving the detents, which may be in the form of a plurality ofgrooves formed on the external surface of the nozzle.

The nozzle preferably comprises a third casing section which defineswith the second casing section the first interior passage. The thirdcasing section is preferably in the form of an outer casing section ofthe nozzle, and the second casing section is preferably in the form ofan inner casing section of the nozzle. The third casing section defineswith the second section the first air outlet(s). The first air outlet(s)are preferably defined by an external surface of the second casingsection and an internal surface of the third casing section. One ofthese surfaces may comprise a plurality of spacers spaced along thatsurface for engaging the other surface to maintain a relatively constantoutlet size along the length of the first air outlet(s). The thirdcasing section preferably defines the base of the second section of thenozzle. The base of the second section of the nozzle preferablycomprises the first air inlet(s) of the nozzle. The base of the secondsection of the nozzle is preferably spaced from the base of thedetachable casing section to facilitate the grasping of the base of thedetachable casing section by the user.

The body may comprise an air flow inlet for admitting at least the firstair flow into the fan assembly. The air flow inlet may comprise a singleaperture, but it is preferred that the air flow inlet comprises aplurality of apertures. These apertures may be provided by a mesh, agrille or other molded component forming part of the external surface ofthe body.

The body preferably comprises a first air passageway for conveying thefirst air flow to the first section of the nozzle, and a second airpassageway for conveying the second air flow to the second section ofthe nozzle. The first air passageway preferably extends from the airflow inlet to the first section of the nozzle. The second air passagewaymay be arranged to receive air directly from the air flow inlet.Alternatively, the second air passageway may be arranged to receive airfrom the first air passageway. In this case, the junction between theair passageways may be located downstream or upstream from the flowgenerating means. An advantage of locating the junction downstream fromthe flow generating means is that the flow generating means may comprisea single impeller and a motor for generating an air flow which isdivided into the first and second air flows downstream from theimpeller.

Preferably, the first air flow is emitted at a first air flow rate andthe second air flow is emitted at a second air flow rate which is lowerthan the first air flow rate.

In a preferred embodiment, the fan assembly comprises a humidifyingsystem which is configured to increase the humidity of the second airflow before it is emitted from the nozzle. To provide the fan assemblywith a compact appearance and with a reduced component number, at leastpart of the humidifying system may be located beneath the nozzle. Atleast part of the humidifying system may also be located beneath theimpeller and the motor. For example, a transducer for atomizing watermay be located beneath the nozzle. This transducer may be controlled bya controller that controls the motor. The body may comprise a removablewater tank for supplying water to the humidifying system. The body maycomprise a base comprising the air inlet and the air flow generatingmeans, and the water tank may be mounted on the base. Preferably, thebase and the water tank each have a curved outer surface, and the outersurfaces of the base and the water tank may have substantially the sameradius. This can further contribute towards the compact appearance ofthe fan assembly.

In a second aspect, the present invention provides a nozzle for a fanassembly, the nozzle comprising having a first section having at leastone first air inlet, at least one first air outlet, and a first interiorpassage for conveying air from said at least one first air inlet to saidat least one first air outlet; and a second section having at least onesecond air inlet, at least one second air outlet, and a second interiorpassage for conveying air from said at least one second air inlet tosaid at least one second air outlet, at least one of the first andsecond sections of the nozzle defining a bore through which air fromoutside the fan assembly is drawn by air emitted from the nozzle, andwherein the second section of the nozzle comprises a detachable casingsection defining, at least in part, the second interior passage.

As described above, a single nozzle may comprise both of the interiorpassages for conveying the air flows to the air outlets. However, thefan assembly may comprise two, substantially concentric nozzles, withone nozzle comprising the features of the first section of the nozzle,and the other nozzle comprising the features of the second section ofthe nozzle. In this case, the fan assembly may comprise a nozzle havinga first casing section, a second casing section, at least one air inlet,at least one air outlet, and an interior passage for conveying air fromsaid at least one air inlet to said at least one air outlet, the nozzledefining a bore through which air from outside the fan assembly is drawnby air emitted from the nozzle, and wherein the first casing section isdetachable from the second casing section, the first casing sectiondefining, at least in part, the interior passage.

In a third aspect, the present invention provides a fan assemblycomprising:

-   -   a nozzle having a first casing section, a second casing section,        at least one air inlet, at least one air outlet, and an interior        passage for conveying air from said at least one air inlet to        said at least one air outlet, the nozzle defining a bore through        which air from outside the fan assembly is drawn by air emitted        from the nozzle; and    -   a body on which the nozzle is detachably mounted, the body        comprising flow generating means for generating an air flow        through the interior passage, and means for changing one of the        humidity and composition of the air flow before it enters the        interior passage;    -   wherein the first casing section is detachable from the second        casing section, the first casing section defining, at least in        part, the interior passage.

In a fourth aspect, the present invention provides a fan assemblycomprising:

-   -   a nozzle having a first casing section, a second casing section,        at least one air inlet, at least one air outlet, and an interior        passage for conveying air from said at least one air inlet to        said at least one air outlet, the nozzle defining a bore through        which air from outside the fan assembly is drawn by air emitted        from the nozzle; and    -   a body on which the nozzle is detachably mounted, the body        comprising flow generating means for generating an air flow        through the interior passage;    -   wherein the first casing section is detachable from the second        casing section, the first casing section defining, at least in        part, the interior passage, and wherein the first casing section        is detachable from the second casing section only when the        nozzle is detached from the body.

Features described above in connection with the first aspect of theinvention are equally applicable to each of the second to fourth aspectsof the invention, and vice versa.

BRIEF DESCRIPTION OF THE INVENTION

An embodiment of the present invention will now be described, by way ofexample only, with reference to the accompanying drawings, in which:

FIG. 1 is a front perspective view of a humidifying apparatus;

FIG. 2 is a front view of the humidifying apparatus;

FIG. 3 is a side view of the humidifying apparatus;

FIG. 4 is a rear view of the humidifying apparatus;

FIG. 5(a) is a top view of a nozzle of the humidifying apparatus, andFIG. 5(b) is a bottom view of the nozzle;

FIG. 6(a) is a top sectional view taken along line B-B in FIG. 2, andFIG. 6(b) is a close-up of area K indicated in FIG. 6(a);

FIG. 7(a) is a side sectional view taken along line E-E in FIG. 5(a),FIG. 7(b) is a close-up of area L indicated in FIG. 7(a), and FIG. 7(c)is a close-up of area M indicated in FIG. 7(a);

FIG. 8 is a front perspective view of the nozzle, with a front casingsection of the nozzle detached from the remainder of the nozzle;

FIG. 9(a) is a perspective view, from above, of the base of thehumidifying apparatus, FIG. 9(b) is a similar view to FIG. 9(a)following a partial rotation of the base, and with an outer wall of thebase partially removed, FIG. 9(c) is a similar view to FIG. 9(a)following a further partial rotation of the base, with a number ofexternal walls of the base partially removed, and FIG. 9(d) is aclose-up of area R indicated in FIG. 9(c);

FIG. 10 is a top view of the base;

FIG. 11 is a side sectional view taken along line A-A in FIG. 2;

FIG. 12 is a perspective rear view, from above, of a water tank mountedon the base, with the handle in a deployed position;

FIG. 13(a) is a rear view of the water tank, FIG. 13(b) is a top view ofthe water tank and FIG. 13(c) is a bottom view of the water tank;

FIG. 14(a) is top view of the water tank mounted on the base, and FIG.14(b) is a front sectional view taken along line D-D in FIG. 14(a);

FIG. 15 is a perspective view of a water reservoir of the base;

FIG. 16(a) is a top view of the water reservoir, and FIG. 16(b) is aside sectional view taken along line C-C in FIG. 16(a);

FIG. 17 is a front perspective view of an upper part of the humidifyingapparatus, with the nozzle of the humidifying apparatus detached fromthe body;

FIG. 18(a) is a front view of the nozzle, and FIG. 18(b) is close-up ofarea N indicated in FIG. 18(a);

FIG. 19(a) is a top view of the humidifying apparatus, FIG. 19(b) is asectional view taken along line F-F in FIG. 19(a), and FIG. 19(c) is asectional view taken along line G-G in FIG. 19(a);

FIG. 20 is a bottom sectional view taken along line H-H in FIG. 4;

FIG. 21(a) is a perspective view of a collar of the base, and FIG. 21(b)is close-up of area P indicated in FIG. 21(a);

FIG. 22 is a schematic illustration of a control system of thehumidifying apparatus; and

FIG. 23 is a flow diagram illustrating steps in the operation of thehumidifying apparatus.

DETAILED DESCRIPTION OF THE INVENTION

FIGS. 1 to 4 are external views of a fan assembly. In this example, thefan assembly is in the form of a humidifying apparatus 10. In overview,the humidifying apparatus 10 comprises a body 12 comprising an air inletthrough which air enters the humidifying apparatus 10, and a nozzle 14in the form of an annular casing mounted on the body 12, and whichcomprises a plurality of air outlets for emitting air from thehumidifying apparatus 10.

The nozzle 14 is arranged to emit two different air flows. The nozzle 14comprises a rear section 16 and a front section 18 connected to the rearsection 16. Each section 16, 18 is annular in shape, and extends about abore 20 of the nozzle 14. The bore 20 extends centrally through thenozzle 14 so that the centre of each section 16, 18 is located on theaxis X of the bore 20.

In this example, each section 16, 18 has a “racetrack” shape, in thateach section 16, 18 comprises two, generally straight sections locatedon opposite sides of the bore 20, a curved upper section joining theupper ends of the straight sections and a curved lower section joiningthe lower ends of the straight sections. However, the sections 16, 18may have any desired shape; for example the sections 16, 18 may becircular or oval. In this embodiment, the height of the nozzle 14 isgreater than the width of the nozzle, but the nozzle 14 may beconfigured so that the width of the nozzle 14 is greater than the heightof the nozzle 14.

Each section 16, 18 of the nozzle 14 defines a flow path along which arespective one of the air flows passes. In this embodiment, the rearsection 16 of the nozzle 14 defines a first air flow path along which afirst air flow passes through the nozzle 14, and the front section 18 ofthe nozzle 14 defines a second air flow path along which a second airflow passes through the nozzle 14.

With reference also to FIGS. 5 to 8, the rear section 16 of the nozzle14 comprises an annular outer casing section 22 connected to andextending about an annular inner casing section 24. Each casing section22, 24 extends about the bore axis X. Each casing section may be formedfrom a plurality of connected parts, but in this embodiment each casingsection 22, 24 is formed from a respective, single moulded part. Eachcasing section 22, 24 is preferably formed from plastics material. Asshown in FIG. 6(b), the front part of the inner casing section 24 has anannular outer wall 24 a which extends generally parallel to the boreaxis X, a front end wall 24 b and an annular intermediary wall 24 cwhich extends generally perpendicular to the bore axis X and which joinsthe outer wall 24 a to the end wall 24 b so that the end wall 24 bprotrudes forwardly beyond the intermediary wall 24 c. During assembly,the external surface of the outer wall 24 a is connected to the internalsurface of the front end of the outer casing section 22, for exampleusing an adhesive.

The outer casing section 22 comprises a tubular base 26 which defines afirst air inlet 28 of the nozzle 14. The outer casing section 22 and theinner casing section 24 together define a first air outlet 30 of thenozzle 14. The first air outlet 30 is defined by overlapping, or facing,portions of the internal surface 32 of the outer casing section 22 andthe external surface 34 of the inner casing section 24. The first airoutlet 30 is in the form of a slot. The slot has a relatively constantwidth in the range from 0.5 to 5 mm. In this example the first airoutlet has a width of around 1 mm. Spacers 36 may be spaced about thefirst air outlet 30 for urging apart the overlapping portions of theouter casing section 22 and the inner casing section 24 to control thewidth of the first air outlet 30. These spacers may be integral witheither of the casing sections 22, 24.

In this embodiment, the first air outlet 30 extends partially about thebore 20. The first air outlet 30 extends along the curved upper sectionand the straight sections of the nozzle 14. However, the first airoutlet 30 may extend fully about the bore 20. The nozzle 14 includes afirst sealing member 38 for inhibiting the emission of the first airflow from the curved lower section of the nozzle 14. In this embodiment,the first sealing member 38 is located on and preferably integral withthe inner casing section 24. The first sealing member 38 is generallyU-shaped. The first sealing member 38 is located on the rear end of theinner casing section 24, and lies in a plane which is substantiallyperpendicular to the axis X. The end of the first sealing member 38engages a U-shaped protrusion 39 extending forwardly from the rear endof the curved lower section of the outer casing section 22 to form aseal therewith.

The first air outlet 30 is arranged to emit air through a front part ofthe bore 20 of the nozzle 14. The first air outlet 30 is shaped todirect air over an external surface of the nozzle 14. In thisembodiment, the external surface 34 of the inner casing section 24comprises a Coanda surface 40 over which the first air outlet 30 isarranged to direct the first air flow. The Coanda surface 40 is annular,and thus is continuous about the central axis X. The external surface 34of the inner casing section 24 also includes a diffuser portion 42 whichtapers away from the axis X in a direction extending from the first airoutlet 30 to the front end 44 of the nozzle 14.

The casing sections 22, 24 together define an annular first interiorpassage 46 for conveying the first air flow from the first air inlet 28to the first air outlet 30. The first interior passage 46 is defined bythe internal surface of the outer casing section 22 and the internalsurface of the inner casing section 24. A tapering, annular mouth 48 ofthe rear section 16 of the nozzle 14 guides the first air flow to thefirst air outlet 30. The first air flow path through the nozzle 14 maytherefore be considered to be formed from the first air inlet 28, thefirst interior passage 46, the mouth 48 and the first air outlet 30.

The front section 18 of the nozzle 14 comprises an annular front casingsection 50. The front casing section 50 extends about the bore axis X,and has a “racetrack” shape which is similar to that of the other casingsections 22, 24 of the nozzle 14. Similar to the casing sections 22, 24,the front casing section 50 may be formed from a plurality of connectedparts, but in this embodiment the front casing section 50 is formed froma single moulded part. The front casing section 50 is preferably formedfrom plastics material. As explained in more detail below, the frontcasing section 50 is detachably attached to the remainder of the nozzle14. In this embodiment, the front casing section 50 is detachablyattached to the inner casing section 24, but depending on thearrangement of the outer casing section 22 and the inner casing section24 the front casing section 50 may be detachably attached to the outercasing section 22. In this embodiment, a snap-fit connection is used toconnect the front casing section 50 to the remainder of the nozzle 14but other methods for connecting the front casing section 50 may beused. For example, one or more magnets may be used to detachably connectthe front casing section 50 to the remainder of the nozzle 14.

The front casing section 50 comprises an annular outer wall 50 a whichextends generally parallel to the bore axis X, an annular inner wall andan annular front wall 50 b which connects the outer side wall 50 a tothe inner wall. The inner wall comprises a front section 50 c whichextends generally parallel to the front wall 24 b of the inner casingsection 24, and a rear section 50 d which is angled to the front section50 c so that the rear section 50 d tapers towards the axis X in adirection extending from the first air outlet 30 to the front end 44 ofthe nozzle 14.

The front casing section 50 comprises a plurality of catches 52extending inwardly from the internal surface of the outer wall 50 a.Each catch 52 is generally cuboid in shape.

The catches 52 are preferably regularly spaced about the bore axis X.The outer wall 24 a of the inner casing section 24 comprises a pluralityof recesses 54 similarly spaced about the bore axis X for receiving thecatches 52. During assembly, the front casing section 50 is pushed on tothe front of the inner casing section 24. The outer wall 50 a deflectselastically outwardly as each catch 52 slides over the outer wall 24 ato enter a respective recess 54. The outer wall 50 a relaxes as thecatches 52 enter the recesses 54, which prevents the catches 52 frombecoming readily removed from the recesses 54, thereby attaching thefront casing section 50 to the inner casing section 24.

The lower end of the front casing section 50 comprises a tubular base56. To subsequently detach the front casing section 50 from the innercasing section 24, the user grasps the base 56 of the front casingsection 50 and pulls the front casing section 50 away from the innercasing section 24. The outer wall 50 a deforms elastically under theforce exerted on the outer wall 50 due to the abutment of the catches 52with the walls of the recesses 54. If a sufficient pulling force isapplied to the front casing section 50 by the user, the outer wall 50 adeforms sufficiently to move the catches 52 out from the recesses 54,thereby allowing the front casing section 50 to move away from the innercasing section 24.

The base 56 defines a plurality of second air inlets 58 of the nozzle14. In this embodiment, the base 56 comprises two second air inlets 58.Alternatively the base 56 may comprises a single air inlet 58. The frontcasing section 50 defines with the inner casing section 24 a second airoutlet 60 of the nozzle 14. In this example, the second air outlet 60extends partially about the bore 20, along the curved upper section andthe straight sections of the nozzle 14. Alternatively, the second airoutlet 60 may extend fully about the bore 20. The second air outlet 60is in the form of a slot having a relatively constant width in the rangefrom 0.5 to 5 mm. In this example the second air outlet 60 has a widthof around 1 mm. The second air outlet 60 is located between the internalsurface of the end wall 24 b of the inner casing section 24 and theexternal surface of the rear section 50 d of the inner wall of the frontcasing section 50. Spacers 62 may be spaced along the second air outlet60 to urge apart the overlapping portions of the inner casing section 24and the front casing section 50 to control the width of the second airoutlet 60. These spacers may be integral with either of the casingsections 24, 50.

The second air outlet 60 is configured to emit the second air flow overthe external surface of the rear section 50 d of the inner wall of thefront casing section 50. This surface thus provides a Coanda surfaceover which each second air outlet 60 is arranged to direct a respectiveportion of the second air flow. This Coanda surface is also continuousabout the axis X, but as the air outlet 60 only extends about part ofthe bore 20 this Coanda surface may similarly extend about part of thebore 20. The external surface of the front section 50 c of the frontcasing section 50 provides a diffuser portion which tapers away from theaxis X in a direction extending from the second air outlet 60 to thefront end 44 of the nozzle 14.

With reference to FIGS. 7(b) and 8, the nozzle 14 comprises a secondsealing member 64 for inhibiting the emission of air from the curvedlower section of the nozzle 14. In this embodiment, the second sealingmember 64 is located on and preferably integral with the front casingsection 50. The second sealing member 64 is generally U-shaped. Thesecond sealing member 64 is located on the curved lower section of thefront casing section 50, and extends rearwardly from the rear section 50d of the inner wall. When the front casing section 50 is attached to theinner casing section 24, the end of the second sealing member 64 locateswithin a U-shaped groove located between the end wall 24 b and theintermediary wall 24 c of the inner casing section 24 to form a sealwith the inner casing section 24.

The casing sections 24, 50 together define an annular second interiorpassage 68 for conveying the second air flow from the second air inlets58 to the second air outlet 60. The second interior passage 68 isdefined by the internal surfaces of the inner casing section 24 and thefront casing section 50. The second air flow path through the nozzle 14may therefore be considered to be formed by the second air inlets 58,the interior passage 68 and the second air outlet 60.

Returning to FIGS. 1 to 4, the body 12 is generally cylindrical inshape. The body 12 comprises a base 70. FIGS. 9 and 10 are externalviews of the base 70. The base 70 has an external outer wall 72 which iscylindrical in shape, and which comprises an air inlet 74. In thisexample, the air inlet 74 comprises a plurality of apertures formed inthe outer wall 72 of the base 70. A front portion of the base 70 maycomprise a user interface of the humidifying apparatus 10. The userinterface is illustrated schematically in FIG. 22, and described in moredetail below. A mains power cable (not shown) for supplying electricalpower to the humidifying apparatus 10 extends through an aperture formedin the base 70.

With reference also to FIG. 11, the base 70 comprises a first airpassageway 76 for conveying a first air flow to the first air flow paththrough the nozzle 14, and a second air passageway 78 for conveying asecond air flow to the second air flow path through the nozzle 14. Thefirst air passageway 76 passes through the base 70 from the air inlet 74to the first air inlet 28 of the nozzle 14. The base 70 comprises a flatbottom wall 80 connected to the lower end of the outer wall 72. Atubular central wall 82, having a smaller diameter than the outer wall72, is connected to the outer wall 72 by an arcuate supporting wall 84.The central wall 82 is substantially co-axial with the outer wall 72.The supporting wall 84 is located above, and generally parallel to, thebottom wall 80. The supporting wall 84 extends partially about thecentral wall 82 to define an opening for receiving a water reservoir 160of the base 70, as described in more detail below. The central wall 82extends upwardly away from the supporting wall 84. In this example, theouter wall 72, central wall 82 and supporting wall 84 are formed as asingle component of the base 70, but alternatively two or more of thesewalls may be formed as a respective component of the base 70. An upperwall of the base 70 is connected to the upper end of the central wall82. The upper wall has a lower frusto-conical section 86 and an uppercylindrical section 88 into which the base 26 of the nozzle 14 isinserted.

The central wall 82 extends about an impeller 90 for generating a firstair flow through the first air passageway 76. In this example theimpeller 90 is in the form of a mixed flow impeller. The impeller 90 isconnected to a rotary shaft extending outwardly from a motor 92 fordriving the impeller 90. In this embodiment, the motor 92 is a DCbrushless motor having a speed which is variable by a drive circuit 94in response to a speed selection by a user. The maximum speed of themotor 92 is preferably in the range from 5,000 to 10,000 rpm. The motor92 is housed within a motor bucket comprising an upper portion 96connected to a lower portion 98. The upper portion 96 of the motorbucket comprises a diffuser 100 in the form of a stationary disc havingcurved blades. The upper wall extends about a plurality of stationaryguide vanes 102 for guiding air emitted from the diffuser 100 towardsthe first air inlet 28 of the nozzle 14. The guide vanes 102 preferablyform part of a single molded component connected to the upper wall ofthe base 70.

The motor bucket is located within, and mounted on, a generallyfrusto-conical impeller housing 104. The impeller housing 104 is, inturn, mounted on an annular platform 106 extending inwardly from thecentral wall 82. An annular inlet member 108 is connected to the bottomof the impeller housing 104 for guiding the air flow into the impellerhousing 104. An annular sealing member 110 is located between theimpeller housing 104 and the platform 106 to prevent air from passingaround the outer surface of the impeller housing 104 to the inlet member108. The platform 106 preferably comprises a guide portion for guidingan electrical cable from the drive circuit 94 to the motor 92.

The first air passageway 76 extends from the air inlet 74 to the inletmember 108. From the inlet member 108, the first air passageway 76extends, in turn, through the impeller housing 104, the upper end of thecentral wall 82 and the sections 86, 88 of the upper wall.

The second air passageway 78 is arranged to receive air from the firstair passageway 76. The second air passageway 78 is located adjacent tothe first air passageway 76.

The second air passageway 78 comprises an inlet duct for receiving airfrom the first air passageway 76. With reference to FIG. 11, the inletduct comprises a first section 110 which is defined by the central wall82 of the base 70. The first section of the inlet duct 110 is locatedadjacent to, and in this example radially external of, part of the firstair passageway 76. The first section 110 of the inlet duct has an inletport 112 located downstream from, and radially outward from, thediffuser 100 so as to receive part of the air flow emitted from thediffuser 100, and which forms the second air flow. With particularreference to FIGS. 9(c) and 9(d), a second section of the inlet duct isdefined by a flexible tube 114. The tube 114 extends between a tubularconnector 116 for receiving air from the first section 110 of the inletduct to a manifold 118. The manifold 118 has an outlet port 120.Optionally, the manifold 118 may be connected by a second flexible tube(not shown) to a second manifold 122 having an outlet port 124. Eachmanifold 118, 122 includes a tubular connector 125 on to which one ofthe second flexible tube is located to place the manifolds 118, 122 influid communication.

The second air passageway 78 further comprises an outlet duct 126 whichis arranged to convey the second air flow to the second air inlets 58 ofthe nozzle 14. The outlet duct 126 comprises two inlet ports 128 locatedin the side wall of the outlet duct 126, towards the lower end thereof.The inlet ports 128 have substantially the same shape as the outletports 120, 124. The outlet duct 126 also comprises two outlet ports 130located at the upper end thereof. Each of the second air inlets 58 ofthe nozzle 14 is arranged to receive air from a respective one of theoutlet ports 130.

The humidifying apparatus 10 is configured to increase the humidity ofthe second air flow before it enters the nozzle 14. With reference nowto FIGS. 1 to 4 and FIGS. 11 to 14, the humidifying apparatus 10comprises a water tank 140 removably mountable on the base 70 of thebody 12. The water tank 140 has a cylindrical outer wall 142 which hasthe same radius as the outer wall 72 of the base 70 of the body 12 sothat the body 12 has a cylindrical appearance when the water tank 140 ismounted on the base 70. The water tank 140 has a tubular inner wall 144which surrounds the walls 82, 86, 88 of the base 70 when the water tank140 is mounted on the base 70. The outer wall 142 and the inner wall 144define, with an annular upper wall 146 and an annular lower wall 148 ofthe water tank 140, an annular volume for storing water. The water tank140 thus surrounds the impeller 90 and the motor 92, and so at leastpart of the first air passageway 76, when the water tank 140 is mountedon the base 70. The lower wall 148 of the water tank 140 engages, and issupported by, the supporting wall 84 of the base 70 when the water tank140 is mounted on the base 70.

The outlet duct 126 passes through the water tank 140. A lower portionof the outlet duct 126 protrudes from the lower wall 148 of the watertank 140, and the inlet ports 128 are located in the side wall of thislower portion of the outlet duct 126. The outlet ports 130 are locatedin a recessed portion 149 of the upper wall 146 of the water tank 140.

The water tank 140 preferably has a capacity in the range from 2 to 4litres. With reference to FIG. 9, a spout 150 is removably connected tothe lower wall 148 of the water tank 140, for example throughco-operating threaded connections. In this example the water tank 140 isfilled by removing the water tank 140 from the base 70 and inverting thewater tank 140 so that the spout 150 is projecting upwardly. The spout150 is then unscrewed from the water tank 140 and water is introducedinto the water tank 140 through an aperture exposed when the spout 150is disconnected from the water tank 140. Once the water tank 140 hasbeen filled, the user reconnects the spout 150 to the water tank 140,returns the water tank 140 to its non-inverted orientation and replacesthe water tank 140 on the base 70. A spring-loaded valve 152 is locatedwithin the spout 150 for preventing leakage of water through a wateroutlet of the spout 150 when the water tank 140 is re-inverted. Thevalve 152 is biased towards a position in which a skirt of the valve 152engages the upper surface of the spout 150 to prevent water entering thespout 150 from the water tank 140.

The upper wall 146 of the water tank 140 comprises one or more supports154 for supporting the inverted water tank 140 on a work surface,counter top or other support surface. In this example, two parallelsupports 154 are formed in the periphery of the upper wall 146 forsupporting the inverted water tank 140.

With reference now to FIGS. 9 to 11 and FIGS. 14 to 16, the base 70comprises a water reservoir 160 for receiving water from the water tank140. The water reservoir 160 is a separate component which is insertedbetween the ends of the supporting wall 84 of the base 70. The waterreservoir 160 comprises an inlet chamber 162 for receiving water fromthe water tank 140, and an outlet chamber 164 for receiving water fromthe inlet chamber 162, and in which water is atomised to becomeentrained within the second air flow. The inlet chamber 162 is locatedon one side of the water reservoir 160, and the outlet chamber 164 islocated on the other side of the water reservoir 160. The waterreservoir 160 comprises a base 166 and a side wall 168 extending aboutand upstanding from the periphery of the base 166. The base 166 isshaped so that the depth of the outlet chamber 164 is greater than thedepth of the inlet chamber 162. The sections of the base 166 locatedwithin each chamber 162, 164 are preferably substantially parallel, andare preferably parallel to the bottom wall 80 of the base 70 so thatthese sections of the base 166 are substantially horizontal when thehumidifying apparatus 10 is located on a horizontal support surface. Theconnector 116 for receiving one end of the flexible tube 114 of theinlet duct is connected to, and preferably integral with, the side wall168 of the water reservoir 160. During assembly, the water reservoir 160is connected to the base 70 so that the upper end of the connector 116is aligned with, and abuts, the lower end of the first section 110 ofthe inlet duct.

The water reservoir 160 is separated into the inlet chamber 162 and theoutlet chamber 164 by a dividing wall 170 which extends partially acrossthe water reservoir 160 from the inner periphery of the side wall 168.An aperture 172 located between the end of the dividing wall 170 and theside wall 166 allows water to pass from the inlet chamber 162 to theoutlet chamber 164.

The dividing wall 170 defines in part the second manifold 122. Theoutlet port 124 is formed in the dividing wall 170 so as to emit part ofthe second air flow into the outlet chamber 164. The manifold 118 islocated on the opposite side of the outlet chamber 164 to the manifold122, and is connected to, and preferably integral with, the side wall166. The outlet port 120 is formed in the side wall 166 so as to emit atleast part of the second air flow into the outlet chamber 164; where thesecond manifold 122 is not connected to the manifold 118 then the outletport 120 will emit all of the second air flow into the outlet chamber164, but otherwise each outlet port 120, 124 will emit part of thesecond air flow into the outlet chamber 164. Each outlet port 120, 124lie in a respective plane P1, P2. Each plane P1, P2 is substantiallyperpendicular to the section of the base 166 defining the outlet chamber164. The planes P1, P2 are arranged so that the plane P1 is inclined atan acute angle to plane P2. In this embodiment, the angle α subtendedbetween the planes P1, P2 is in the range from 30 to 70°. The outletports 120, 124 have substantially the same shape, and are located at thesame vertical distance from the section of the base 166 defining theoutlet chamber 164.

With reference to FIGS. 14(a) and 14(b), when the water tank 140 ismounted on the base 70 the lower portion of the outlet duct 126 extendsinto the outlet chamber 164. The lower portion of the outlet duct 126 isshaped so that each inlet ports 128 of the outlet duct 126 is alignedwith a respective outlet port 120, 124 of the inlet duct so that airemitted from each outlet port 120, 124 passes immediately through arespective inlet port 128 of the outlet duct 126 to enter the outletduct 126.

Returning to FIGS. 15 and 16, a pin 174 extends upwardly from thesection of the base 166 defining the inlet chamber 162. When the watertank 140 is mounted on the base 70, the pin 174 protrudes into the spout150 to push the valve 152 upwardly to open the spout 150, therebyallowing water to pass under gravity into the inlet chamber 162. As theinlet chamber 162 fills with water, water passes through the aperture172 to enter the outlet chamber 164. As water is output from the watertank 140, it is replaced within the water tank 140 by air which entersthe water tank 140 through a slot 175 located in the side wall of thespout 150. As the chambers 162, 164 fill with water, the level of waterwithin the chambers 162, 164 equalizes. The spout 150 is arranged sothat the water reservoir 160 can be filled with water to a maximum levelwhich is substantially co-planar with the upper end of the slot 175located within the side wall of the spout 150; above that level no aircan enter the water tank 140 to replace water output from the water tank140. This maximum water level is preferably selected so that at leastpart of each outlet port 120, 124 of the inlet duct lies above thismaximum water level. As a result, the second air flow enters the waterreservoir 160 directly over the surface of the water located in theoutlet chamber 164 of the water reservoir 160.

The section of the base 166 defining the outlet chamber 164 comprises acircular aperture for exposing a piezoelectric transducer 176. The drivecircuit 94 is configured to actuate vibration of the transducer 176 inan atomization mode to atomise water located in the outlet chamber 164.In the atomization mode, the transducer 176 may vibrate ultrasonicallyat a frequency f₁, which may be in the range from 1 to 2 MHz.

The water reservoir 160 also includes an ultraviolet radiation (UV)generator for irradiating water within the water reservoir 160. In thisembodiment, the UV generator is arranged to irradiate water within theoutlet chamber 164 of the water reservoir 160. The UV generator is inthe form of a UV lamp 180 located within a UV transparent tube 182. Thetube 182 is in turn located within the outlet chamber 164. The tube 182may be wholly located within the outlet chamber 164. Preferably, one endof the tube 182 protrudes through an aperture formed in the side wall168 of the water reservoir 160 to expose one or more electricalconnectors 184 that allow electrical connections to be made between thedrive circuit 94 and the UV lamp 180. An O-ring sealing member may beprovided between the tube 182 and the aperture formed in the side wall168 to inhibit water leakage through the aperture. The UV generator ispositioned within the outlet chamber 164 along a portion of the sidewall 168 positioned adjacent to the aperture 172 through which waterenters the outlet chamber 164.

The water reservoir 160 comprises a baffle plate 186 for guiding waterentering the outlet chamber 164 along the tube 182. The baffle plate 186extends across the outlet chamber 164 from the dividing wall 170 to theportion of the side wall 166 in which the outlet port 120 is formed, andserves to divide the outlet chamber 164 into an inlet section 164 a forreceiving water from the inlet chamber 162, and an outlet section 164 bwithin which water is atomized by the transducer 176. The baffle plate186 is shaped so that the lower edge of the baffle plate 186 engages thetube 182 along the length thereof. The lower edge of the baffle plate186 thus divides the outer surface of the tube 182 into an upper portionlocated within the inlet section 164 a to one side of the baffle plate186, and a lower portion located within the outlet section 164 b to theother side of the baffle plate 186. The upper portion of the tube 182delimits a lower surface of the inlet section 164 a of the outletchamber 164, and the lower portion of the tube 182 delimits part of aside surface of the outlet section 164 b of the outlet chamber 164. Aswater enters the outlet chamber 164, it is guided by the baffle plate186 to flow along the inlet section 164 a, adjacent the upper portion ofthe tube 182. A notch formed in the lower edge of the baffle plate 186defines with the tube 182 an aperture 188 through which water flows fromthe inlet section 164 a to the outlet section 164 b.

The upper edge of the baffle plate 186 is located above the maximumwater level of the water reservoir 160 A level sensor 190 (illustratedschematically in FIG. 22) is located within the water reservoir 160 fordetecting the level of water within the water reservoir 160. The base 70may also include a proximity sensor 192 for detecting that the watertank 140 has been mounted on the base 70. The proximity sensor 192 maybe in the form of a reed switch which interacts with a magnet (notshown) located on the lower wall 148 of the water tank 140 to detect thepresence, or absence, of the water tank 140 on the base 70.

As illustrated in FIG. 12, when the water tank 140 is mounted on thebase 70 the inner wall 144 surrounds the upper wall of the base 70 toexpose the open upper end of the upper cylindrical section 88 of theupper wall. The water tank 140 includes a handle 194 to facilitateremoval of the water tank 140 from the base 70. The handle 194 ispivotably connected to the water tank 140 so as to be moveable relativeto the water tank 140 between a stowed position, in which the handle 194is housed within a recessed section 196 of the upper wall 146 of thewater tank 140, and a deployed position, in which the handle 194 israised above the upper wall 146 of the water tank 140. One or moreresilient elements, such as torsion springs, may be provided in therecessed section 196 of the upper wall 146 for biasing the handle 194towards its deployed position, as illustrated in FIG. 12.

With reference to FIG. 17, when the nozzle 14 is mounted on the body 12,the base 26 of the outer casing section 22 of the nozzle 14 is locatedover the open end of the upper cylindrical section 88 of the upper wallof the base 70, and the base 56 of the front casing section 50 of thenozzle 14 is located over the recessed portion 149 of the upper wall 146of the water tank 140. The user then pushes the nozzle 14 towards thebody 12 so that the base 26 enters the upper cylindrical section 88 ofthe upper wall of the base 70. Simultaneously, the lower externalsurface of the outer casing section 22 pushes the handle 194 towards itsstowed position, against the biasing force of the resilient elements. Aprotrusion may be provided on the lower external surface of the outercasing section 22 to engage the handle 194 as the nozzle 14 is pushed onto the body 12.

When the bases 26, 56 of the nozzle 14 are fully inserted in the body12, a first annular sealing member 198 forms an air tight seal betweenthe lower end of the base 26 and an annular ledge 200 extending radiallyinwardly from the cylindrical section 88 of the upper wall of the base70. Second sealing members 202 located within the recessed section 149of the upper wall 146 of the water tank 140 198 form air tight sealsbetween the lower end of the base 56 and the periphery of the outletports 130. The upper wall 146 of the water tank 140 has a concave shapeso that, when the nozzle 14 is mounted on the body 12, the water tank140 surrounds a lower part of the nozzle 14. This not only can thisallow the capacity of the water tank 140 to be increased, but can alsoprovide the humidifying apparatus 10 with a compact appearance.

A mechanism is provided for releasably retaining the nozzle 14 on thebody 12. With reference to FIGS. 17 to 21, in this embodiment the base70 of the body 12 comprises the mechanism for releasably retaining thenozzle 14 on the body 12. The mechanism for releasably retaining thenozzle 14 on the body 12 comprises a hoop 210 located within a cavity212 defined by the cylindrical section 88 of the upper wall of the base70. The cavity 212 is located between an inner section 214 and an outersection 216 of the cylindrical section 88 of the upper wall of the base70. The inner section 214 comprises a plurality of angularly spaced,co-planar slots 218. In this embodiment, the inner section 214 comprisesthree slots 218. The hoop 210 comprises a plurality of detents 220extending radially inwardly from the inner surface of the hoop 210. Eachdetent 220 protrudes through a respective one of the slots 218. The hoop210 is rotatable within the cavity 212 to enable the detents 220 to movealong the slots 218. Each detent 220 is moveable between a first,retaining position for retaining the nozzle 14 on the body 12, and asecond, release position for allowing the nozzle 14 to be removed fromthe body 12. Resilient elements are provided for biasing the detents 220towards their retaining positions. In this example, the resilientelements are in the form of helical tension springs 222. Each spring 222has one end connected to a respective pin 224 depending downwardly fromthe lower end of the hoop 210, and the other end connected to arespective pin 226 depending downwardly from the outer section 216 ofthe cylindrical section 88 of the upper wall of the base 70.

The outer surface of the base 26 of the nozzle 14 comprises a pluralityof recesses 228 each for receiving the distal end of a respective detent220. Each recess 228 is shaped so as to have a lower, open end 230, anupper, closed end 232, a first side wall having an inclined section 234extending from the lower end 230 and a horizontal section 236 extendingfrom the inclined section 234 to the closed end 232, and a second,generally vertical second side wall 238 opposite to the first side wall.

As the nozzle 14 is mounted on the body 12, each detent 220 engages thelower end of the inclined section 234 of the side wall of a respectiverecess 228. With further depression of the nozzle 14 on to the body 12,the force applied to the detents 220 by the side walls of the recesses228 causes the hoop 210 to rotate relative to the nozzle 14, against thebiasing force applied thereto by the springs 222, to allow the detents220 to move from their retaining positions along the inclined sections234 of the recesses 228. As the detents 220 reach the upper ends of theinclined sections 234 of the recesses 228, the force applied to thedetents 220 by the side wall of the recesses 228 is removed. The springs222 relax, and urge the hoop 210 to rotate within the cavity 212 toreturn the detents 220 rapidly to their retaining positions. The detents220 thus become located at the closed ends 232 of the recesses 228. Thebiasing force applied to the hoop 210 by the springs 222 keeps thedetents 220 in their retained positions. In the event that a user shouldattempt to lift the humidifying apparatus 10 by grasping the nozzle 14and pulling the nozzle 14 upwards, the engagement of the detents 220with the horizontal sections 236 of the recesses 228 prevents the nozzle14 from becoming detached from the body 12.

The body 12 comprises a depressible button 240 for moving the detents220 from their retaining positions to their release positions to allowthe nozzle 14 to be removed from the body 12. In this example, thebutton 240 is located on the base 70, and is moveable within a housing242 defined by the upper wall of the base 70. The water tank 140 isshaped so that the upper surface of the button 240 is substantiallyflush with the upper wall 146 of the water tank 140 when the water tank140 is mounted on the base 70 and the button 240 is in the raisedposition.

A notch having an inclined surface 244 is formed on the lower end of thebutton 240. A finger 246 provided on the outer surface of the hoop 210extends into the notch so that the finger 246 engages the lower end ofthe inclined surface 244 of the notch. Depression of the button 240 bythe user causes the inclined surface 244 of the notch to apply a forceto the finger 246, which in turn causes the hoop 210 to rotate relativeto the nozzle 14, against the biasing force applied thereto by thesprings 222. This rotation of the hoop 210 moves the detents 220 alongthe horizontal sections 236 of the recesses 228 from their retainingpositions to their release positions, in which the detents 220 arelocated adjacent the second side walls 238 of the recesses 228. Whilethe detents 220 are maintained in their release positions, through thedepression of the button 240 by the user, the user may pull the nozzle14 from the body 12. With this relative movement between the nozzle 14and the body 12, the second side walls 238 of the recesses 228 slidealong the detents 220 to disengage the detents 220 from the recesses228, and so release the nozzle 14 from the body 12. Once the nozzle 14has been lifted from the body 12, the button 240 may be released by theuser. The springs 222 urge the hoop 210 to rotate within the cavity 212to move the detents 220 back to their retaining positions. An additionalspring may be located beneath the button 240 to urge the button 240 backto its raised position.

As the nozzle 14 is lifted from the body 12, the resilient elementwithin the water tank 140 urges the handle 194 to its deployed position.The user can then use the handle 194 to lift the water tank 140 from thebase 70 to allow the water tank 140 to be filled or cleaned as required.One or more sections of the water tank 140 are preferably removable tofacilitate cleaning of the water tank 140. For example, a section 250 ofthe outlet duct 126 may be removed from the water tank 140 to allow theinternal surfaces of the outlet duct 126 to be cleaned. While the nozzle14 is removed from the body, 12, the user may clean the internalsurfaces of the second interior passage 68 of the nozzle 14 by pullingthe front section 50 of the nozzle 14 from the inner casing section 24of the nozzle 14 to expose the internal surfaces of the second interiorpassage 68. Once the water tank 140 has been filled or cleaned, the userreplaces the water tank 140 on the base 70, and then replaces the nozzle14 on the body 12.

A user interface (not shown) for controlling the operation of thehumidifying apparatus may be located on the outer wall 72 of the base 70of the body 12. Alternatively, or additionally, the humidifyingapparatus 10 may comprise a remote control 260 for transmitting controlsignals to a user interface circuit 262 of the humidifying apparatus 10.FIG. 22 illustrates schematically a control system for the humidifyingapparatus 10, which includes the remote control 260, the user interfacecircuit 262 and other electrical components of the humidifying apparatus10. In overview, the remote control 260 comprises a plurality of buttonswhich are depressible by the user, and a control unit for generating andtransmitting infrared light signals in response to depression of one ofthe buttons. The infrared light signals are emitted from a windowlocated at one end of the remote control 260. The control unit ispowered by a battery located within a battery housing of the remotecontrol 260.

A first button is used to activate and deactivate the motor 92, and asecond button is used to set the speed of the motor 92, and thus therotational speed of the impeller 90. The control system may have adiscrete number of user selectable speed settings, each corresponding toa respective different rotational speed of the motor 92. A third buttonis used to set a desired level for the relative humidity of theenvironment in which the humidifying apparatus 10 is located, such as aroom, office or other domestic environment. For example, the desiredrelative humidity level may be selected within a range from 30 to 80% at20° C. through repeated actuation of the third button.

The user interface circuit 262 comprises a sensor or receiver 264 forreceiving signals transmitted by the remote control 260, and a display266 for displaying a current operational setting of the humidifyingapparatus 10. For example, the display 266 may normally indicate thecurrently selected relative humidity level. As the user changes therotational speed of the motor 92, the display 266 may indicate brieflythe currently selected speed setting. The receiver 264 and the display266 may be located immediately behind a transparent or translucent partof the outer wall 72 of the base 70.

The user interface circuit 262 is connected to the drive circuit 94. Thedrive circuit 94 comprises a microprocessor and a motor driver fordriving the motor 92. A mains power cable (not shown) for supplyingelectrical power to the humidifying apparatus 10 extends through anaperture formed in the base 70. The cable is connected to a plug. Thedrive circuit 94 comprises a power supply unit connected to the cable.The user interface may also comprise one or more LEDs for providing avisual alert depending on a status of the humidifying apparatus 10. Forexample, a first LED 268 may be illuminated to indicate that the watertank 140 has become depleted, as indicated by a signal received by thedrive circuit 94 from the level sensor 190.

A humidity sensor 270 is also provided for detecting the relativehumidity of air in the external environment, and for supplying a signalindicative of the detected relative humidity to the drive circuit 94. Inthis example the humidity sensor 270 may be located immediately behindthe air inlet 74 to detect the relative humidity of the air flow drawninto the humidifying apparatus 10. The user interface may comprise asecond LED 272 which is illuminated by the drive circuit 94 when anoutput from the humidity sensor 270 indicates that the relative humidityof the air flow entering the humidifying apparatus 10, H_(D), is at orabove the desired relative humidity level, H_(S), set by the user.

With reference also to FIG. 23, to operate the humidifying apparatus 10,the user actuates the first button of the remote control, in response towhich the remote control 260 generates a signal containing dataindicative of the actuation of this first button. This signal isreceived by the receiver 264 of the user interface circuit 262. Theoperation of the button is communicated by the user interface circuit262 to the drive circuit 94, in response to which the drive circuit 94actuates the UV lamp 180 to irradiate water stored in the outlet chamber164 of the water reservoir 160. In this example, the drive circuit 94simultaneously activates the motor 92 to rotate the impeller 90. Therotation of the impeller 90 causes air to be drawn into the body 12through the air inlet 74. An air flow passes through the impellerhousing 104 and the diffuser 100. Downstream from the diffuser 100, aportion of the air emitted from the diffuser 100 enters the inlet ductthrough the inlet port 112, whereas the remainder of the air emittedfrom the diffuser 100 is conveyed along the first air passageway 76 tothe first air inlet 28 of the nozzle 14. The impeller 90 and the motor92 may thus be considered to generate a first air flow which is conveyedto the nozzle 14 by the first air passageway 76 and which enters thenozzle 14 through the first air inlet 28.

The first air flow enters the first interior passage 46 at the lower endthereof. The first air flow is divided into two air streams which passin opposite directions around the bore 20 of the nozzle 14. As the airstreams pass through the first interior passage 46, air enters the mouth48 of the nozzle 14. The air flow rate into the mouth 48 is preferablysubstantially even about the bore 20 of the nozzle 14. The mouth 48guides the air flow towards the first air outlet 30 of the nozzle 14,from where it is emitted from the humidifying apparatus 10.

The air flow emitted from the first air outlet 30 causes a secondary airflow to be generated by the entrainment of air from the externalenvironment, specifically from the region around the first air outlet 30and from around the rear of the nozzle 14. Some of this secondary airflow passes through the bore 20 of the nozzle 14, whereas the remainderof the secondary air flow becomes entrained, in front of the nozzle 14,within the air flow emitted from the first air outlet 30.

As mentioned above, with rotation of the impeller 90 air enters thesecond air passageway 78 through the inlet port 112 of the inlet duct toform a second air flow. The second air flow passes through the inletduct and is emitted through the outlet ports 120. 124 over the waterstored in the outlet section 164 b of the outlet chamber 164. Theemission of the second air flow from the outlet ports 120, 124 agitatesthe water stored in the outlet section 164 b of the outlet chamber 164.This generates movement of water in front of the lower portion of thetube 182 of the UV generator, increasing the volume of water which isirradiated by the UV lamp 180 prior to actuation of the transducer 176.The relative inclination of the outlet ports 120, 124 can enable thesecond air flow to generate a swirling motion of water in the outletsection 164 b of the outlet chamber 164 to convey water alongside thelower portion of the tube 182.

In addition to the agitation of the water stored in the outlet chamber164 by the second air flow, the agitation may also be performed by thevibration of the transducer 176 in an agitation mode which isinsufficient to cause atomization of the stored water. Depending, forexample on the size and the number of transducers 176, the agitation ofthe stored water may be performed solely by vibration of the transducer176 at a reduced second frequency f₂, and/or at a reduced amplitude, orwith a different duty cycle. In this case, the drive circuit 94 may beconfigured to actuate the vibration of the transducer 176 in thisagitation mode simultaneously with the irradiation of the stored waterby the UV lamp 180.

The agitation and irradiation of the stored water continues for a periodof time sufficient to reduce the level of bacteria within the outletchamber 164 of the water reservoir 160 by a desired amount. In thisexample, the outlet chamber 164 has a maximum capacity of 200 ml, andthe agitation and irradiation of the stored water continues for a periodof 120 seconds before atomization of the stored water commences. Theduration of this period of time may be lengthened or shortened dependingon, for example, the degree of agitation of the stored water, thecapacity of the outlet chamber 164 of the water reservoir 160, and theintensity of the irradiation of the stored water, and so depending onthese variables the duration of this period of time may take any valuein the range of 10 to 300 seconds to achieve the desired reduction inthe number of bacteria within the stored water.

At the end of this period of time, the drive circuit 94 actuates thevibration of the transducer 176 in the atomization mode to atomize waterstored in the outlet section 164 b of the outlet chamber 164 of thewater reservoir 160. This creates airborne water droplets above thewater located within the outlet chamber 164 of the water reservoir 160.In the event that the stored water was agitated previously by vibrationof the transducer 176 alone, the motor 92 is also activated at this endof this period of time.

As water within the water reservoir 160 is atomized, the water reservoir160 is constantly replenished with water received from the water tank140 via the inlet chamber 162, so that the level of water within thewater reservoir 160 remains substantially constant while the level ofwater within the water tank 140 gradually falls. As water enters theoutlet chamber 164 from the inlet chamber 162, it is guided by thebaffle plate 186 to flow along the upper portion of the tube 182 so thatit is irradiated with ultraviolet radiation emitted from the upperportion of the tube 182 before passing through aperture 188 locatedbetween the tube 182 and the baffle plate 186. This water is thenfurther irradiated with ultraviolet radiation emitted from the lowerportion of the tube 182 before being atomized by the transducer 176. Thedirection of the movement of the water within the outlet chamber 164, asgenerated by the second air flow and/or the vibration of the transducer176, is preferably such that the water flows from the aperture 188 alongthe lower portion of the tube 182, and in a direction generally oppositeto that in which water flows along the upper portion of the tube 182,before being atomized by the transducer 176.

With rotation of the impeller 90, airborne water droplets becomeentrained within the second air flow emitted from the outlet ports 120,124 of the inlet duct. The—now moist—second air flow passes upwardlythrough the outlet duct 126 of the second air passageway 78 to thesecond air inlets 58 of the nozzle 14, and enters the second interiorpassage 68 within the front section 18 of the nozzle 14.

At the base of the second interior passage 68, the second air flow isdivided into two air streams which pass in opposite directions aroundthe bore 20 of the nozzle 14. As the air streams pass through the secondinterior passage 68, each air stream is emitted from the second airoutlet 60. The emitted second air flow is conveyed away from thehumidifying apparatus 10 within the air flow generated through theemission of the first air flow from the nozzle 14, thereby enabling ahumid air current to be experienced rapidly at a distance of severalmetres from the humidifying apparatus 10.

The moist air flow is emitted from the nozzle 14 until the relativehumidity H_(D) of the air flow entering the humidifying apparatus 10, asdetected by the humidity sensor 270, is 1% at 20° C. higher than therelative humidity level H_(S), selected by the user using the thirdbutton of the remote control 260. The emission of the moistened air flowfrom the nozzle 14 may then be terminated by the drive circuit 94,preferably by changing the mode of vibration of the transducer 176. Forexample, the frequency of the vibration of the transducer 176 may bereduced to a frequency f₃, where f₁>f₃≥0, below which atomization of thestored water is not performed. Alternatively the amplitude of thevibrations of the transducer 176 may be reduced. Optionally, the motor92 may also be stopped so that no air flow is emitted from the nozzle14. However, when the humidity sensor 270 is located in close proximityto the motor 92 it is preferred that the motor 92 is operatedcontinually to avoid undesirable humidity fluctuation in the localenvironment of the humidity sensor 270. Also, it is preferred tocontinue to operate the motor 92 to continue agitating the water storedin the outlet section 164 b of the outlet chamber 164 of the waterreservoir 160. Operation of the UV lamp 180 is also continued.

As a result of the termination of the emission of a moist air flow fromthe humidifying apparatus 10, the relative humidity H_(D) detected bythe humidity sensor 270 will begin to fall. Once the relative humidityof the air of the environment local to the humidity sensor 270 hasfallen to 1% at 20° C. below the relative humidity level H_(S) selectedby the user, the drive circuit 94 re-activates the vibration of thetransducer 176 in the atomization mode. If the motor 92 has beenstopped, the drive circuit 94 simultaneously re-activates the motor 92.As before, the moist air flow is emitted from the nozzle 14 until therelative humidity H_(D) detected by the humidity sensor 270 is 1% at 20°C. higher than the relative humidity level H_(S) selected by the user.

This actuation sequence of the transducer 176 (and optionally the motor92) for maintaining the detected humidity level around the levelselected by the user continues until the first button is actuated again,or until a signal is received from the level sensor 190 indicating thatthe level of water within the water reservoir 160 has fallen below theminimum level. If the first button is actuated, or upon receipt of thissignal from the level sensor 190, the drive circuit 94 deactivates themotor 92, the transducer 176 and the UV generator to switch off thehumidifying apparatus 10. The drive circuit 94 also deactivates thesecomponents of the humidifying apparatus 10 in response to a signalreceived from the proximity sensor 192 indicating that the water tank140 has been removed from the base 70.

The invention claimed is:
 1. A fan assembly comprising: a nozzle havinga first casing section with a first base comprising at least one firstair inlet, a second casing section with a second base comprising atleast one second air inlet, at least one air outlet, and an interiorpassage for conveying air from said at least one first air inlet or saidat least one second air inlet to said at least one air outlet, thenozzle defining a bore through which air from outside the fan assemblyis drawn by air emitted from the nozzle, wherein one of the first casingsection and the second casing section comprises a plurality of catchesspaced about the bore and the other one of the first casing section andthe second casing section comprises a plurality of recesses similarlyspaced about the bore for receiving the plurality of catches and whereinthe first casing section forms the front of the nozzle and is in frontof the second casing section and the front of the nozzle is a portion ofthe nozzle that is the most downstream from the air flow emitted fromthe at least one air outlet; and a body on which the nozzle isdetachably mounted such that the first base and second base are insertedin the body when the nozzle is mounted on the body, the body comprisinga flow generating device for generating an air flow through the interiorpassage, and a humidifying system for humidifying the air flow before itenters the interior passage; wherein the first casing section isdetachable from the second casing section, the first casing sectiondefining, at least in part, the interior passage.
 2. The fan assembly ofclaim 1, wherein the first casing section is arranged to define, atleast in part, said at least one air outlet.
 3. The fan assembly ofclaim 1, wherein the first casing section is annular in shape.
 4. Thefan assembly of claim 1, wherein both of the first and second casingsections define said bore.
 5. The fan assembly of claim 1, wherein saidat least one air outlet is arranged to emit air over at least part ofthe first casing section.
 6. The fan assembly of claim 1, wherein thefirst casing section is detachably attached to the second casing sectionby a snap-fit connection.
 7. The fan assembly of claim 1, wherein thesecond casing section defines with the first casing section said atleast one air outlet.
 8. The fan assembly of claim 1, wherein the bodycomprises a water tank and the first base is inserted into a portion ofthe water tank when the nozzle is mounted on the body.
 9. A fan assemblycomprising: a nozzle having a first section comprising a first casingsection with a first base comprising at least one first air inlet, atleast one first air outlet, and a first interior passage for conveyingair from said at least one first air inlet to said at least one firstair outlet; and a second section having at least one second air inlet,at least one second air outlet, and a second interior passage forconveying air from said at least one second air inlet to said at leastone second air outlet, at least one of the first and second sections ofthe nozzle defining a bore through which air from outside the fanassembly is drawn by air emitted from the nozzle; and a body on whichthe nozzle is mounted, the body comprising a flow generating device forgenerating a first air flow through the first interior passage and asecond air flow through the second interior passage, and a humidifyingsystem for humidifying the second air flow before it enters the secondinterior passage; wherein the second section of the nozzle comprises asecond casing section with a second base comprising the at least onesecond air inlet and defining, at least in part, the second interiorpassage, wherein one of the first casing section and the second casingsection comprises a plurality of catches spaced about the bore and theother one of the first casing section and the second casing sectioncomprises a plurality of recesses similarly spaced about the bore forreceiving the plurality of catches, and wherein the first base andsecond base are inserted in the body when the nozzle is mounted on thebody and wherein the first casing section forms the front of the nozzleand is in front of the second casing section and the front of the nozzleis a portion of the nozzle that is the most downstream from the air flowemitted from the at least one first air outlet and the at least onesecond air outlet.
 10. The fan assembly of claim 9, wherein the secondcasing section comprises said at least one second air inlet.
 11. The fanassembly of claim 9, wherein the second casing section is annular inshape.
 12. The fan assembly of claim 9, wherein both of the first andsecond sections of the nozzle define said bore.
 13. The fan assembly ofclaim 9, wherein each of said at least one first air outlet and said atleast one second air outlet is arranged to emit air over at least partof the second casing section.
 14. The fan assembly of claim 9, whereinthe nozzle comprises the second casing section which defines with thesecond casing section the second interior passage, and wherein thesecond casing section is detachably attached to the second casingsection.
 15. The fan assembly of claim 14, wherein the first casingsection is detachably attached to the second casing section by asnap-fit connection.
 16. The fan assembly of claim 14, wherein thesecond casing section defines with the first casing section said atleast one second air outlet.
 17. The fan assembly of claim 14, whereinthe second casing section defines, at least in part, the first interiorpassage.
 18. The fan assembly of claim 17, wherein the second casingsection defines, at least in part, said at least one first air outlet.19. The fan assembly of claim 14, wherein the nozzle comprises adiffuser located downstream from said at least one first air outlet, andwherein the second casing section comprises a first portion of thediffuser and the first casing section comprises a second portion of thediffuser.
 20. The fan assembly of claim 19, wherein said at least onesecond air outlet is located between the first portion of the diffuserand the second portion of the diffuser.
 21. The fan assembly of claim14, wherein the nozzle is detachable from the body, and wherein thefirst casing section is detachable from the second casing section onlywhen the nozzle is detached from the body.
 22. The fan assembly of claim14, wherein the first base is graspable by a user to detach the firstcasing section from the second casing section.
 23. The fan assembly ofclaim 9, wherein the body comprises a water tank and the first base isinserted into a portion of the water tank when the nozzle is mounted onthe body.
 24. A fan assembly comprising: a nozzle having a first casingsection with a first base comprising at least one first air inlet, asecond casing section with a second base comprising at least one secondair inlet, at least one air outlet, and an interior passage forconveying air from said at least one first air inlet or said at leastone second air inlet to said at least one air outlet, the nozzledefining a bore through which air from outside the fan assembly is drawnby air emitted from the nozzle, wherein one of the first casing sectionand the second casing section comprises a plurality of catches spacedabout the bore and the other one of the first casing section and thesecond casing section comprises a plurality of recesses similarly spacedabout the bore for receiving the plurality of catches; and a body onwhich the nozzle is detachably mounted such that the first base and thesecond base are inserted in the body when the nozzle is mounted on thebody, the body comprising a flow generating device for generating an airflow through the interior passage; wherein the first casing section isdetachable from the second casing section and wherein the first casingsection forms the front of the nozzle and is in front of the secondcasing section and the front of the nozzle is a portion of the nozzlethat is the most downstream from the air flow emitted from the at leastone air outlet, the first casing section defining, at least in part, theinterior passage, and wherein the first casing section is detachablefrom the second casing section only when the nozzle is detached from thebody.
 25. The fan assembly of claim 24, wherein the first casing sectionis arranged to define, at least in part, said at least one air outlet.26. The fan assembly of claim 24, wherein the first casing section isannular in shape.
 27. The fan assembly of claim 24, wherein both of thefirst and second casing sections define said bore.
 28. The fan assemblyof claim 24, wherein said at least one air outlet is arranged to emitair over at least part of the first casing section.
 29. The fan assemblyof claim 24, wherein the first casing section is detachably attached tothe second casing section by a snap-fit connection.
 30. The fan assemblyof claim 24, wherein the first base is graspable by a user to detach thefirst casing section from the second casing section.
 31. The fanassembly of claim 24, wherein the body comprises a water tank and thefirst base is inserted into a portion of the water tank when the nozzleis mounted on the body.